We invoke an efficient search algorithms as a key challenge in multi-qubit quantum systems. An original algorithm called dynamical quantum search algorithm from which Grover algorithm is obtained at a specified time is presented. This algorithm is distinguished by accuracy in obtaining high probability of finding any marked state in a shorter time than Grover algorithm time. The algorithm performance ... إقراء المزيد

Following experimental work [Nature, 473, 194 (2011)], we propose a new physical scheme for perfect implementation of a quantum search algorithm in the presence of qubits dissipation. It is shown that the Grover algorithm is obtained as a special case of the suggested quantum search algorithm. We have generated the quantum gates to realize the required steps for implementing the ... إقراء المزيد

In this paper, we propose a useful practical way to investigate and control the amount of entanglement in multipartite systems using the spin coherent states (SCSs). Using the M-Flip concurrence as a measure of entanglement, we derive the amount of entanglement and examine its properties in terms of different parameters involved in the SCSs and giving conditions under which tripartite ... إقراء المزيد

We exploit a scheme to obtain a long-lived entanglement using a driven central spin interacting with an antiferromagnetic spin bath. Our numerical results show the effects of different parameters on the population inversion and the entanglement dynamics in terms of the linear entropy. It is shown that the long-lived entanglement is an intriguing result corresponding to the collapse region of ... إقراء المزيد

We present rigorous investigations of the geometric phase in semiconductor microcavities. The effects of excitonic spontaneous emission, initial state setting and cavity dissipation have been discussed. It is shown that the geometric phase decays exponentially due to the presence of excitonic spontaneous emission. More importantly, the inclusion of the phase shift leads to an enhanced sensitivity for the control of ... إقراء المزيد

Classifying researchers according to the quality of their published work rather than the quantity is a curtail issue. We attempt to introduce a new formula of the percentage range to be used for evaluating qualitatively the researchers' production. The suggested equation depends on the number of the singleauthor published papers and their citations to be added as a new factor ... إقراء المزيد

Given a perfect superposition of [Formula: see text] states on a quantum system of [Formula: see text] qubits. We propose a fast quantum algorithm for collapsing the perfect superposition to a chosen quantum state [Formula: see text] without applying any measurements. The basic idea is to use a phase destruction mechanism. Two operators are used, the first operator applies a ... إقراء المزيد

We consider a multi-qubit system consisting of two trapped ions coupled in a laser field. The ions are identical three-level electronic systems which interact with one another through the phonon modes of their relative or center of mass motions, and the system is tuned so that two-phonon processes dominate the electronic transitions. The resulting evolution of the system is studied ... إقراء المزيد

Any set of pure states living in an given Hilbert space possesses a natural and unique metric –the Haar measure– on the group U(N) of unitary matrices. However, there is no specific measure induced on the set of eigenvalues ∆ of any density matrix ρ. Therefore, a general approach to the global properties of mixed states depends on the specific ... إقراء المزيد

We investigate the entropy squeezing and entanglement of the Cooper-pair box interacting with multi-photon cavity field. The field is prepared initially in the coherent state, while the Cooper-pair box is assumed to start from a mixed state. We find that the number of photons and the detuning parameters play an important role in the entropy squeezing and entanglement. We observe ... إقراء المزيد